1. Field of the Invention
The present invention relates to monolithic ceramic electronic components, and particularly, to a monolithic ceramic electronic component including at least two types of stacked ceramic layers having different dielectric constants.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2005-191129 discloses a monolithic ceramic electronic component including two types of stacked ceramic layers which have different dielectric constants and which are made of different materials, and internal electrodes partially disposed along boundaries between the ceramic layers. Monolithic ceramic electronic components including such ceramic layers made of different materials have the following problems.
In a calcination step for manufacturing a monolithic ceramic electronic component including ceramic layers made of different materials, a problem with the interdiffusion of the different materials between the ceramic layers often occurs. In the case in which internal electrodes are partially disposed along boundaries between ceramic layers made of different materials, when the ceramic layers and the internal electrodes are calcined together, the internal electrodes have a suppressive action on interdiffusion. However, this causes an increased amount of interdiffusion between portions having no internal electrodes. Therefore, a ceramic present outside the internal electrodes is altered, and therefore, the internal electrodes and the ceramic layers are likely to be deformed due to differences in the timing of shrinkage during calcination.
The disadvantage described above causes a problem in that the electrical properties exhibited by monolithic ceramic electronic components are deteriorated or variations in the electrical properties are increased, and particularly, causes a problem that when a monolithic ceramic electronic component is a capacitor, the capacitance of the capacitor is reduced or variations in the capacitance thereof is increased.
The disadvantage adversely affects the adhesion between ceramic layers made of different materials so as to cause delamination or interfacial separation between the ceramic layers.
It has been proposed to provide dummy electrodes or dummy ceramic layers between ceramic layers made of different materials to prevent the interdiffusion. However, providing the dummy electrodes or the dummy ceramic layers therebetween prevents a reduction in the size or the profile of monolithic ceramic electronic components.